Polymer composition, its process of preparation and its use

ABSTRACT

The present invention relates to a polymeric composition comprising an impact modifier, a processing aid and a mineral filler and its process of preparation and its use. In particular the present invention relates to a polymeric composition comprising an impact modifier, a processing aid and a mineral filler and its use for thermoplastic polymers. More particularly the present invention relates to the process of preparation of polymeric composition comprising an impact modifier, a processing aid and a mineral filler and its use for the transformation and/or processing of thermoplastic polymers.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national stage application under 35 U.S.C. § 371of PCT/EP2017/063841, filed Jun. 7, 2017 which claims benefit toapplication FR 16 55199, filed Jun. 7, 2016.

FIELD OF THE INVENTION

The present invention relates to a polymeric composition comprising animpact modifier, a processing aid and a mineral filler and its processof preparation and its use.

In particular the present invention relates to a polymeric compositioncomprising an impact modifier, a processing aid and a mineral filler andits use for thermoplastic polymers.

More particularly the present invention relates to the process ofpreparation of polymeric composition comprising an impact modifier, aprocessing aid and a mineral filler and its use for the transformationand/or processing of thermoplastic polymers.

Technical Problem

Many kind of additives and fillers are used in thermoplastic polymercompositions in general and in halogenated polymer compositions inparticular for a large variety of reasons. They can extend thecomposition, increase stiffness and strength, and shorten cycle times.They prevent hang-up in dies and neutralize the products of degradation.Fillers can also be used to add color, opacity and conductivity or theycan be used as a low cost material that lowers the cost of thecomposition as the filler is less expensive than the other ingredientsof the formulation.

However the addition of additives and filler to thermoplastic polymers,especially when several are added at the same time or mixtures of them,can also change characteristics of that thermoplastic polymercomposition in a negative direction, meaning loss or important decreaseof certain characteristic or behavior.

Polymer compositions comprising polymers with specific characteristic(such as polymer composition, glass transition temperature or specificmolecular weight range just for naming some characteristics) are used asadditives for thermoplastic polymer compositions in general and inhalogenated polymer compositions in particular in order to enhance theprocessing behavior of these various polymers compositions or plasticresin or to improve their transformation and/or processing performance.Therefor these additives are also called processing aids.

Processing aids in small quantities in thermoplastic polymercompositions in general and in halogenated polymer compositions inparticular can improve the processing characteristics through anacceleration of the fusion process of said thermoplastic polymercompositions in general and of halogenated polymer compositions inparticular.

Again other polymer compositions comprising polymers with specificcharacteristic (such as polymer composition, glass transitiontemperature or structure for naming some characteristics) are also usedas additives for thermoplastic polymer compositions in general and inhalogenated polymer compositions in particular in order to improve theimpact resistance of the composition or object made out of these variouspolymers or plastic resin. Therefor these additives are also calledimpact modifiers.

The additive polymer composition is compatible with thermoplasticpolymer compositions in general and in halogenated polymer compositionsin particular.

The objective of the present invention is to propose a polymericcomposition which can be added to thermoplastic polymers as an additive.

The objective of the present invention is as well to propose a polymericcomposition which acts as impact modifier and processing aid at the sametime.

An objective of the present invention is also to have a polymercomposition that can be used to increase the melt fracture resistance ofthermoplastic polymers.

Another objective of the present invention is also to have a polymercomposition that can be used to increase the productivity of extrusionof thermoplastic polymers.

An additional objective of the present invention is the reduction of theprice of a polymer composition which acts as processing aid and impactmodifier at the same time for thermoplastic polymer compositions byaddition of low cost components without negatively influencing theperformance of the thermoplastic polymer compositions.

Still another objective of the present invention is a method formanufacturing a polymer composition which acts as impact modifier andprocessing aid at the same time and increase the productivity ofextrusion of thermoplastic polymers.

Still an additional objective is having a process for preparing apolymer composition that can be used to increase the productivity oftransformation of polymer compositions and to increase the impactstrength.

BACKGROUND OF THE INVENTION Prior Art

The document US 2009/0111915 discloses acrylic copolymers for use inhighly filled compositions. In particular the document disclosed filledpolyvinylchloride (PVC) materials as a composition for flooringcomprising 70 wt % to 95 wt % filler, 1 wt % to 15 wt % PVC and 0.5 wt %to 4 wt % of acrylic copolymer or a composition for siding or pipecomprising 15 wt % to 35 wt % filler, 50 wt % to 95 wt % PVC and 0.25 to6 wt % of acrylic copolymer.

The document WO 2010/099160 discloses composite polymer modifiers. Thedocument discloses a composite polymer modifier consisting of 99 wt % to1 wt % of inorganic filler and from 1 wt % to 99 wt % of a polymericprocessing aid and 0 wt % to 80% of an impact modifier. The impactmodifier is optional, however used in some examples. This documentdiscloses no specific advantages about certain impact modifiercompositions.

The document U.S. Pat. No. 3,373,229 discloses vinyl polymercompositions. The compositions comprises polyvinyl chloride and highmolecular weight polymers of methyl methacrylate or copolymers of methylmeth acrylate with a small amount of an alkyl acrylate as processingaid. The composition might comprise a filler.

None of the prior art documents discloses such a specific polymercomposition comprising an inorganic compound, a (meth)acrylic copolymerand a polymeric impact modifier, neither its process of preparation orits use.

BRIEF DESCRIPTION OF THE INVENTION

Surprisingly it has been found that a polymer composition P1 comprising

-   -   a) from 30 wt % to 60 wt % of an inorganic compound (F),    -   b) from 2 wt % 15 wt % a (meth)acrylic copolymer (A1) and    -   c) a polymeric impact modifier (IM1);        characterized that the three components of a), b) and c) add up        to 100 wt %, increases the melt fracture resistance of        thermoplastic polymers while giving good impact properties.

Surprisingly it has also been found that a process for preparing apolymer composition P1 comprising

-   -   a) from 30 wt % to 60 wt % of an inorganic compound (F)    -   b) from 2 wt % 15 wt % a (meth)acrylic copolymer (A1)    -   c) a polymeric impact modifier (IM1);        characterized that the three components of a), b) and c) add up        to 100 wt %, said process comprises the step of    -   blending the three components a), b) and c), while the two        components of b) and c) and at least 83.33 wt % of compound        of a) are in form of a dispersion in aqueous phase during the        blending step;        yields to a polymer composition that increases the melt fracture        resistance of thermoplastic polymers while giving good impact        properties.

Surprisingly it has also been found that a process for preparing apolymer composition P1 comprising

-   -   a) from 30 wt % to 60 wt % of an inorganic compound (F)    -   b) from 2 wt % 15 wt % a (meth)acrylic copolymer (A1)    -   c) a polymeric impact modifier (IM1);        characterized that the three components of a), b) and c) add up        to 100 wt %, said process comprises the step of    -   i) blending the three components of a), b) and c), while the two        components of b) and c) and at least 83.33 wt % of compound a)        are in form of a dispersion in aqueous phase during the blending        step,    -   ii) drying the blend obtained in step i);        yields to a polymer composition that increases the melt fracture        resistance of thermoplastic polymers while giving good impact        properties.

Surprisingly it has also been found that a polymer composition P1comprising

-   -   a) from 30 wt % to 60 wt % of an inorganic compound (F)    -   b) from 2 wt % 15 wt % a (meth)acrylic copolymer (A1)    -   c) a polymeric impact modifier (IM1);        characterized that the three components of a), b) and c) add up        to 100 wt %, can be used to increase the productivity of the        extrusion of thermoplastic polymers.

DETAILED DESCRIPTION OF THE INVENTION

According to a first aspect, the present invention relates to a polymercomposition P1 comprising

-   -   a) from 30 wt % to 60 wt % of an inorganic compound (F),    -   b) from 2 wt % 15 wt % a (meth)acrylic copolymer (A1) and    -   c) a polymeric impact modifier (IM1);        characterized that the three components of a), b) and c) add up        to 100 wt %.

According to a second aspect, the present invention relates to a polymercomposition P1 comprising

-   -   a) from 30 wt % to 60 wt % of an inorganic compound (F),        -   said inorganic compound (F) consists of a mineral filler            (F1) and a flow aid (F2), wherein the weight ratio (F1)/(F2)            is at least 5/1,    -   b) from 2 wt % 15 wt % a (meth)acrylic copolymer (A1) and    -   c) a polymeric impact modifier (IM1);        characterized that the three components of a), b) and c) add up        to 100 wt %.

In a third aspect the present invention relates to a process forpreparing a polymeric composition P1 comprising

-   -   a) from 30 wt % to 60 wt % of an inorganic compound (F)    -   b) from 2 wt % 15 wt % a (meth)acrylic copolymer (A1)    -   c) a polymeric impact modifier (IM1)        characterized that the three components a), b) and c) add up to        100 wt %, said process comprises the step of    -   blending the three components of a), b) and c), while the two        components of b) and c) and at least 83.33 wt % of compound a)        are in form of a dispersion in aqueous phase during the blending        step.

In a fourth aspect the present invention relates to a process forpreparing a polymeric composition P1 comprising

-   -   a) from 30 wt % to 60 wt % of an inorganic compound (F) said        inorganic compound (F) consists of a mineral filler (F1) and a        flow aid (F2), wherein the weight ratio (F1)/(F2) is at least        5/1,    -   b) from 2 wt % 15 wt % a (meth)acrylic copolymer (A1) and    -   c) a polymeric impact modifier (IM1);        characterized that the three components of a), b) and c) add up        to 100 wt %, said process comprises the step of    -   blending the three components a), b) and c), while the three        components of b), c) and mineral filler (F1) are in form of a        dispersion in aqueous phase during the blending step.

In a fifth aspect the present invention relates to a process forpreparing a polymeric composition P1 comprising

-   -   a) from 30 wt % to 60 wt % of an inorganic compound (F)    -   b) from 2 wt % 15 wt % a (meth)acrylic copolymer (A1)    -   c) a polymeric impact modifier (IM1) characterized that the        three components of a), b) and c) add up to 100 wt %, said        process comprises the step of    -   i) blending the three components of a), b) and c), while the two        components of b) and c) and at least 83.33 wt % of compound a)        are in form of a dispersion in aqueous phase during the blending        step,    -   ii) drying the blend obtained in step i).

In a sixth aspect the present invention relates to a process forpreparing a polymeric composition P1 comprising

-   -   a) from 30 wt % to 60 wt % of an inorganic compound (F) said        inorganic compound (F) consists of a mineral filler (F1) and a        flow aid (F2), wherein the weight ratio (F1)/(F2) is at least        5/1,    -   b) from 2 wt % 15 wt % a (meth)acrylic copolymer (A1) and    -   c) a polymeric impact modifier (IM1);        characterized that the three components of a), b) and c) add up        to 100 wt %, said process comprises the step of    -   i) blending the three components a), b) and c), while the three        components of b), c) and mineral filler (F1) are in form of a        dispersion in aqueous phase during the blending step    -   ii) drying the blend obtained in step i).

In a seventh aspect the present invention relates to a process forpreparing a polymeric composition P2 comprising polymer composition P1,said polymer composition P1 comprises

-   -   a) from 30 wt % to 60 wt % of an inorganic compound (F)    -   b) from 2 wt % 15 wt % a (meth)acrylic copolymer (A1)    -   c) a polymeric impact modifier (IM1),        characterized that the three components of a), b) and c) add up        to 100 wt %, and the said polymeric composition P2 comprises        also    -   d) a thermoplastic polymer TP1 said process comprises the step        of    -   blending the compositions P1 and the thermoplastic polymer TP1.

In a eighth aspect the present invention relates to the use of apolymeric composition P1 comprising

-   -   a) from 30 wt % to 60 wt % of an inorganic compound (F)    -   b) from 2 wt % 15 wt % a (meth)acrylic copolymer (A1)    -   c) a polymeric impact modifier (IM1),        characterized that the three components of a), b) and c) add up        to 100 wt %, for increasing the melt fracture resistance of a        thermoplastic polymer TP1.

In a ninth aspect the present invention relates to the use of apolymeric composition P1 comprising

-   -   a) from 30 wt % to 60 wt % of an inorganic compound (F)    -   b) from 5 wt % 15 wt % a (meth)acrylic copolymer (A1)    -   c) a polymeric impact modifier (IM1),        characterized that the three components of a), b) and c) add up        to 100 wt %, for transforming a polymeric composition P2 that        comprises said polymeric composition P1 and a thermoplastic        polymer TP1.

By the term “polymeric composition” as used is denoted that thecomposition consists of polymers of at least 40 wt %.

By the term “copolymer” as used is denoted that the polymer consists ofat least two different monomers.

By the term “(meth)acrylic” as used is denoted all kind of acrylic andmethacrylic monomers.

By the term “(meth)acrylic polymer” as used is denoted that the(meth)acrylic) polymer comprises essentially polymers comprising(meth)acrylic monomers that make up 50 wt % or more of the (meth)acrylicpolymer.

By the term “polymer powder” as used is denoted a polymer comprisingpowder grain in the range of at least 1 micrometer (μm) obtained byagglomeration of primary polymer comprising particles in the nanometerrange.

By the term “primary particle” as used is denoted a spherical shapepolymer comprising particle in the nanometer range. Preferably theprimary particle has a weight average particle size between 20 nm and500 nm.

By “multistage polymer” as used is denoted a polymer formed insequential fashion by a multi-stage polymerization process. Preferred isa multi-stage emulsion polymerization process in which the first polymeris a first-stage polymer and the second polymer is a second-stagepolymer, i.e., the second polymer is formed by emulsion polymerizationin the presence of the first emulsion polymer.

By the term “dispersion” as used is denoted a colloidal system with acontinuous liquid phase and a discontinuous solid phase that isdistributed throughout the continuous phase.

By the term “emulsion” as used is denoted a liquid/liquid mixture of aliquid discontinuous phase in a liquid continuous phase.

By the term “PVC” as used is understood polyvinyl chloride in form ofhomopolymer or copolymer comprising at least 50 wt % of vinyl chloride.

By the term “filler” as used is understood a solid extender added to apolymer in order to enhance properties and/or reduce costs.

By the term “flow aid” as used is understood an anti caking agent, thatallows a good flow ability of the powder and avoids caking.

By the abbreviation “phr” is meant parts per hundred parts of resin. Forexample 15 phr of filler in a PVC formulation means that 15 kg of fillerare added to 100 kg of PVC.

By “that the three components of a), b) and c) add up to 100 wt %” asused, is meant that the ratio of the three components of a), b) and c)is only calculated from the sum of these three components. If there areother additional components outside of a), b) and c), they are not takeninto account for the calculation of the weight ratio between the threeof them.

By saying that a range from x to y in the present invention, it is meantthat the upper and lower limit of this range are included, equivalent toat least x and up to y.

By saying that a range is between x and y in the present invention, itis meant that the upper and lower limit of this range are excluded,equivalent to more than x and less then y.

With regard to the polymeric composition P1 of the present invention, itcomprises at least three components a) from 30 wt % to 60 wt % of aninorganic compound (F), b) from 2 wt % to 15 wt % a (meth)acryliccopolymer (A1) and c) a polymeric impact modifier (IM1) latter chosen ina relative quantity so that the three components add up to 100 wt %. Thecomponent c) the polymeric impact modifier (IM1) in the polymericcomposition P1 is between 25 wt % and 68 wt %.

The component b) could also be a mixture of several (meth)acryliccopolymers (A1) to (Ax). Each (meth)acrylic copolymer having a specificdifferent characteristic.

The component c) could also be a mixture of several polymeric impactmodifiers (IM1) to (IMx). Each polymeric impact modifier having aspecific different characteristic.

Preferably the polymeric composition P1 comprises a) between 30 wt % and60 wt % of an inorganic compound (F), b) between 2 wt % and 15 wt % a(meth)acrylic copolymer (A1) and c) a polymeric impact modifier (IM1)latter chosen in a relative quantity so that the three components add upto 100 wt %.

The inorganic compound (F) consists of a mineral filler (F1) and a flowaid (F2), wherein the weight ratio (F1)/(F2) is at least 5/1.

More preferably the composition P1, of the present invention comprisesa) between 30 wt % and 60 wt % of an inorganic compound (F), b) between2 wt % and 12 wt % a (meth)acrylic copolymer (A1) and c) a polymericimpact modifier (IM1) latter chosen in a relative quantity so that thethree components add up to 100 wt %. Still more preferably thecomposition P1 comprises a) between 30 wt % and 50 wt % of an inorganiccompound (F), b) between 3 wt % and 10 wt % a (meth)acrylic copolymer(A1) and c) a polymeric impact modifier (IM1) latter chosen in arelative quantity so that the three components add up to 100 wt %.

Advantageously the composition P1, of the present invention comprises a)between 40 wt % and 50 wt % of an inorganic compound (F), b) between 4wt % and 10 wt % a (meth)acrylic copolymer (A1) and c) a polymericimpact modifier (IM1) latter chosen in a relative quantity so that thethree components add up to 100 wt %.

The polymeric composition P1 according to the invention is preferably inform of a powder comprising the three components. The powder is composedof grains of aggregated particles of the three components. Theseparticles are the primary particles.

With regard to the polymer powder of the invention, it has a volumemedian particle size D50 between 1 μm and 500 μm. Preferably the volumemedian particle size of the polymer powder is between 10 μm and 450 μm,more preferably between 15 μm and 400 μm and advantageously between 20μm and 300 μm.

The D10 of the particle size distribution in volume is at least 7 μm andpreferably 10 μm.

The D90 of the particle size distribution in volume is at most 800 μmand preferably at most 500 μm.

The powder according to the invention is homogenous in view of thecomposition concerning the three components.

Homogeneous in the present invention signifies no important variationthroughout the composition. If one or several small samples (1 g or lesscomprising several powder grain particles) is/are taken from a largerquantity (1 kg) of the composition there is no important variation ofthe composition concerning the weight ratio of the three respectivecomponents in the small sample in comparison to other small samples andthe global composition. By no important variation is meant that thevariation is less than 30% relative to the global composition. As anexample, if the global composition P1 comprises 40 wt % of the inorganiccompound (F), 10 wt % of the (meth)acrylic copolymer (A1) and 50 wt % ofthe polymeric impact modifier (IM1), a small first sample taken from theglobal composition that would comprise 35% wt of the inorganic compound(F), 11% of the (meth)acrylic copolymer (A1) and 54 wt % of thepolymeric impact modifier (IM1) or small second sample taken from theglobal composition that would comprise 42% wt of the inorganic compound(F), 10% of the (meth)acrylic copolymer (A1) and 48 wt % of thepolymeric impact modifier (IM1), would signify a homogenous compositionas the variation of ratio of the respective components throughout thesmall samples is within the 30% variation in view of the globalcomposition of the sample.

Preferably the variation of the components within the composition isless than 25%, more preferably less than 20%.

In an ideal case each powder particle or grain comprises all threecomponents a), b) and c) and is composed of aggregated particles of thethree components.

The polymer composition P1 according to the present invention which ispreferably in form of a powder, is more preferably a dry powder. By dryis meant that the powder has a certain maximum level of humidity.

The dry polymer composition P1 in form of a powder according to thepresent invention comprises less than 3 wt % humidity and preferablyless than 1.5 wt % humidity and more preferably less than 1.2 wt %humidity.

The dry polymer composition P1 in form of a powder according to thepresent invention can comprise additionally a flow aid (F2). The flowaid (F2) is preferably an inorganic compound. Therefor the flow aid (F2)is part of the inorganic compound (F) of the composition P1. Theinorganic compound (F) is consisting of the flow aid (F2) and aninorganic filler (F1): (F)=(F1)+(F2) The quantity of the flow aid (F2)is much less important in the polymer composition P1 than the inorganicfiller (F1). The quantity of (F1) is at least 5 times more importantthan the quantity of (F2)

The density of the polymer composition P1 is at least 1.25 g/cm3,preferably at least 1.3 g/cm3 and more preferably at least 1.33 g/cm3.

The density of the polymer composition P1 is at most 1.75 g/cm3,preferably at most 1.7 g/cm3 and more preferably at most 1.67 g/cm3.

Advantageously the density of the polymer composition P1 is between 1.25g/cm3 and 1.75 g/cm3, and more advantageously between 1.3 g/cm3 and 1.7g/cm3.

With regard to the inorganic compound (F) it is either an inorganicfiller or mineral filler (F1) or it comprises both an inorganic filleror mineral filler (F1) and a flow aid (F2).

Preferably the inorganic compound (F) comprises a mineral filler (F1)and a flow aid (F2). More preferably the weight ratio (F1)/(F2) is atleast 5/1.

With regard to the mineral filler (F1), mention may be made of glassfibers, hollow glass microspheres, inorganic compounds, such as mineralsand salts including calcium carbonate (CaCO₃), silica, silicates such ascalcium silicate or metasilicate, clay such as bentonite, mica, talc,alumina trihydrate, magnesium hydroxide, metal oxides, or combinationsof two or more thereof.

Preferably the mineral filler (F1) is chosen from calcium carbonate,titanium dioxide or calcinated clay, silica (fumed or precipitated),clay, Montmorillonite (nano-clay), zeolite, perlite or any other type ofinorganic material that can be obtained as a slurry.

More preferably the mineral filler (F1) is chosen from calciumcarbonate, calcinated clay, silica (fumed or precipitated), clay,Montmorillonite (nano-clay), zeolite or perlite.

The mineral filler (F1) of the inorganic compound (F) could also be amixture of several mineral fillers (F1a) to (F1x).

In a still more preferred embodiment the mineral filler (F1) is calciumcarbonate (CaCO3).

Advantageously the calcium carbonate is chosen from precipitated calciumcarbonate (PCC), grinded natural calcium carbonate (GCC) or nanosizedparticles of precipitated calcium carbonate (NPCC).

The mineral filler (F1) or at least a part of the mineral filler (F1)could also be in form of a slurry for the process for preparing thepolymeric composition P1.

Preferably the filler (F1) or at least a part of the mineral filler(F1), that is blended with the (meth)acrylic copolymer (A1) and thepolymeric impact modifier (IM1), is in form of a slurry.

As regards the slurry of the mineral filler, it is a water dispersion ofa mineral filler with solid content preferably between 5 wt % and 90 wt% and advantageously between 50 wt % and 80 wt %. This water dispersioncan contain any specific surfactant, dispersing agent, additive orfiller surface treatment that can advantageously improve the quality ofthe slurry (stability, viscosity or compatibility with the host polymermatrix).

With regard to the flow aid (72) it is an inorganic powder.

The flow aid (F2) could also be a mixture of several flow aid (F2a) to(F2x).

Advantageously the flow aid (F2) is chosen from calcium carbonate(CaCO3).

With regard to the (meth)acrylic copolymer (A1), it is a (meth) acryliccopolymer comprising at least 50 wt % of polymeric units coming frommethyl methacrylate.

Preferably the (meth)acrylic copolymer (A1) has a glass transitiontemperature of less than 106° C.

More preferably the polymer (A1) comprises a comonomer or comonomerswhich are copolymerizable with methyl methacrylate, as long as polymer(A1) is having a glass transition temperature of less than 106° C.

The comonomer or comonomers in copolymer (A1) are preferably chosen from(meth)acrylic and/or vinyl monomers.

The (meth)acrylic comonomer in (meth)acrylic copolymer (A1) comprisesmonomers chosen from C1 to C12 alkyl (meth)acrylates. Still morepreferably (meth)acrylic comonomer in polymer (A1) comprises monomers ofC1 to C4 alkyl methacrylate and/or C1 to C8 alkyl acrylate monomers.

Most preferably the acrylic or methacrylic comonomers of the(meth)acrylic copolymer (A1) or the two (meth)acrylic copolymers (A1a)and (A1b) are chosen from methyl acrylate, propyl acrylate, isopropylacrylate, butyl acrylate, tert-butyl acrylate, methyl methacrylate,ethyl methacrylate, butyl methacrylate and mixtures thereof, as long asmeth)acrylic copolymer (A1) or the mixture of two (meth)acryliccopolymers (Ala) and (A1b) is having a glass transition temperature ofless than 106° C.

Preferably the (meth)acrylic copolymer (A1) comprises at most 90 wt %,more preferably at most 85 wt % and advantageously at most 81 wt % ofpolymeric units coming from methyl methacrylate.

In a specific embodiment the (meth)acrylic copolymer (A1) is a copolymerof methyl methacrylate with ethyl acrylate and/or butyl acrylate.

More preferably the glass transition temperature Tg of the (meth)acrylicpolymer (A1) comprising at least 50 wt % of polymeric units coming frommethyl methacrylate is between 60° C. and 106° C., even more preferablybetween 65° C. and 100° C. and advantageously between 70° C. and 100° C.

The glass transition temperature Tg can be estimated for example bydynamic methods as thermo mechanical analysis.

Preferably the mass average molecular weight Mw of the (meth)acryliccopolymer (A1) or the two (meth)acrylic copolymers (Ala) and (A1b)comprising at least 50 wt % of polymeric units coming from methylmethacrylate is at least 1 000 000 g/mol, preferably at least 1 500 000g/mol, more preferably at least 2 000 000 g/mol, advantageously at least2 500 000 g/mol and most advantageously at least 3 000 000 g/mol.

Preferably the mass average molecular weight Mw of the (meth)acryliccopolymer (A1) or the two (meth)acrylic copolymers (Ala) and (A1b)comprising at least 50 wt % of polymeric units coming from methylmethacrylate is less than 10 000 000 g/mol, preferably less than 9 000000 g/mol, more preferably less than 8 000 000 g/mol, advantageouslyless than 8 500 000 g/mol and most advantageously at 7 000 000 g/mol.

The (meth)acrylic copolymer (A1) comprising at least 50 wt % ofpolymeric units coming from methyl methacrylate is preferably preparedby an emulsion polymerisation, yielding to an aqueous dispersion ofspherical shape polymer particles of the (meth)acrylic copolymer (A1).

A possible variation of the method for preparing an aqueous dispersionof spherical shape polymer particles comprising the (meth)acryliccopolymer (A1) is by using a multistage process.

During one stage of the multistage process the (meth)acrylic copolymer(A1) is prepared.

With regard to the spherical shaped polymer particle comprising the(meth)acrylic copolymer (A1), it has a weight average particle sizebetween 20 nm and 500 nm. Preferably the weight average particle size ofthe polymer is between 50 nm and 400 nm, more preferably between 75 nmand 350 nm and advantageously between 80 nm and 300 nm.

With regard to the polymeric impact modifier (IM1), it is preferably apolymer particle having a multilayer structure.

The polymer particle having a multilayer structure is more or lessspherical shape. The polymer particle has a weight average particle size(diameter) between 20 nm and 500 nm. Preferably the weight averageparticle size of the polymer particle is between 50 nm and 400 nm, morepreferably between 75 nm and 350 nm and advantageously between 80 nm and300 nm.

The polymer particle according to the invention is obtained by amultistage process such as two or three stages or more stages, eachstage yield to a layer, the whole process yields to a particle with amultilayer structure

The polymeric impact modifier (IM1) in form of the polymeric particlehaving a multilayer structure comprising at least one layer (IM1L1)comprising a polymer (L1) having a glass transition temperature below 0°C. and at least another layer (IM1L2) comprising a polymer (L2) having aglass transition temperature over 45° C.

More preferably the glass transition temperature Tg of the polymer (L1)is between −100° C. and 0° C., even more preferably between −80° C. and0° C. and advantageously between −80° C. and −20° C. and moreadvantageously between −70° C. and −20° C.

Preferably the glass transition temperature Tg of the polymer (L2) isbetween 60° C. and 150° C. The glass transition temperature of thepolymer (L2) is more preferably between 80° C. and 140° C.,advantageously between 90° C. and 135° C. and more advantageouslybetween 90° C. and 130° C.

In order to obtain a sample of the respective polymers (L1) and (L2)they can be prepared alone, and not by a multistage process, forestimating and measuring more easily the glass transition temperature Tgindividually of the respective polymers of the respective stages.

The weight ratio of layer (IM1L1)/layer (IM1L2) in the multistagepolymer is preferably at least 70/30, more preferably at least 80/20,even more preferably at least 85/15, advantageously at least 86/14, moreadvantageously 87/13, even more advantageously 88/12 and mostadvantageously 89/11.

The weight ratio of layer (IM1L1)/layer (IM1L2) in the multistagepolymer is preferably in a range by weight between 70/30 and 99/1, morepreferably 80/20 and 98/2, even more preferably 85/15 and 97/3,advantageously 86/14 and 97/3, more advantageously 87/13 and 97/3, evenmore advantageously 88/12 and 97/3 and most advantageously 89/11 to96/4.

Preferably the polymer L1 presents more than 85 wt % of the polymericimpact modifier (IM1) and more preferably more than 86 wt % andadvantageously more than 87 wt %.

The multi-layer structure of IM1 can have different structures. Thelayer (IM1L1) comprising a polymer (L1) having a glass transitiontemperature below 0° C., can be the core of the polymeric impactmodifier (IM1) or an intermediate layer, but never the most outer layer.The layer (IM1L2) comprising a polymer (L2) having a glass transitiontemperature over 45° C. can be the most outermost layer.

The layer (IM1L2) comprising a polymer (L2) is preferably a (meth)acrylic copolymer comprising at least 50 wt % of polymeric units comingfrom methyl methacrylate. Preferably the polymer (L2) or the majority ofthe polymer (L2) of the layer (IM1L2) is grafted on the layer situatedbelow.

In a first preferred embodiment of (IM1), the polymer (L1) having aglass transition temperature below 0° C. is a (meth) acrylic polymercomprising at least 50 wt % of monomers from alkyl acrylates.

More preferably the polymer (L1) comprises a comonomer or comonomerswhich are copolymerizable with alkyl acrylate, as long as polymer (A1)is having a glass transition temperature of less than 0° C.

The comonomer or comonomers in polymer (L1) are preferably chosen from(meth)acrylic monomers and/or vinyl monomers.

The (meth)acrylic comonomer in polymer (L1) comprises monomers chosenfrom C1 to C12 alkyl (meth)acrylates. Still more preferably(meth)acrylic comonomer in polymer (L1) comprises monomers of C1 to C4alkyl methacrylate and/or C1 to C8 alkyl acrylate monomers.

Most preferably the acrylic or methacrylic comonomers of the polymer(L1) are chosen from methyl acrylate, propyl acrylate, isopropylacrylate, butyl acrylate, tert-butyl acrylate, methyl methacrylate,ethyl methacrylate, butyl methacrylate and mixtures thereof, as long aspolymer (L1) is having a glass transition temperature of less than 0° C.

Preferably the polymer (L1) is crosslinked. This means that acrosslinker is added to the other monomer or monomers. A crosslinkercomprises at least two groups that can be polymerized.

In one specific embodiment polymer (L1) is a homopolymer of butylacrylate.

In another specific embodiment polymer (L1) is a copolymer of butylacrylate and at least one crosslinker. The crosslinker presents lessthan 5 wt % of this copolymer.

More preferably the glass transition temperature Tg of the polymer (L1)of the first embodiment is between −100° C. and 0° C., even morepreferably between −100° C. and −5° C., advantageously between −90° C.and −15° C. and more advantageously between −90° C. and −25° C.

In a second preferred embodiment the polymer (L1) having a glasstransition temperature below 0° C. comprises at least 50 wt % ofpolymeric units coming from isoprene or butadiene and the stage or layer(IML1) is the most inner layer of the polymer particle having themultilayer structure. In other words the stage for making the layer(IM1L1) comprising a polymer (L1) is the core of the polymer particle.

By way of example, the polymer (L1) of the core of the secondembodiment, mention may be made of isoprene homopolymers or butadienehomopolymers, isoprene-butadiene copolymers, copolymers of isoprene withat most 98 wt % of a vinyl monomer and copolymers of butadiene with atmost 98 wt % of a vinyl monomer. The vinyl monomer may be styrene, analkylstyrene, acrylonitrile, an alkyl (meth)acrylate, or butadiene orisoprene. In one embodiment the core is a butadiene homopolymer.

More preferably the glass transition temperature Tg of the polymer (L1)of the second embodiment comprising at least 50 wt % of polymeric unitscoming from isoprene or butadiene is between −100° C. and 0° C., evenmore preferably between −100° C. and −5° C., advantageously between −90°C. and −15° C. and even more advantageously between −90° C. and −25° C.

With regard to the thermoplastic polymer TP1 it is chosen from halogencontaining polymers, such as for example polyvinyl chloride, polyamide,polymethyl methacrylate, polystyrene, polycarbonate, polyesters such aspolyethylene terephthalate, polybutylene terephthalate,polycyclohexanedimethanol terephthalate, and polyolefins.

In a first preferred embodiment the thermoplastic polymer TP1 is ahalogen containing polymer.

With regard to the halogen containing polymer, mention may be made of:

-   -   homopolymers and copolymers of vinyl chloride (PVC) and of        vinylidene chloride (PVDC), vinyl resins comprising vinyl        chloride units in their structure, such as copolymers of vinyl        chloride, and vinyl esters of aliphatic acids, especially vinyl        acetate, copolymers of vinyl chloride with esters of acrylic and        methacrylic acid and with acrylonitrile, copolymers of vinyl        chloride with diene compounds and unsaturated dicarboxylic acids        or their anhydrides, such as copolymers of vinyl chloride with        diethyl maleate, diethyl fumarate or maleic anhydride,        post-chlorinated polymers and copolymers of vinyl chloride,        copolymers of vinyl chloride and vinylidene chloride with        unsaturated aldehydes, ketones and others, such as acrolein,        crotonaldehyde, vinyl methyl ketone, vinyl methyl ether, vinyl        isobutyl ether and the like; polymers of vinylidene chloride and        its copolymers with vinyl chloride and other polymerizable        compounds;    -   polymers of vinyl chloroacetate and dichlorodivinyl ether;        chlorinated polymers of vinyl carboxylate, such as vinyl        acetate, vinyl propionate, vinyl butyrate, chlorinated polymeric        esters of acrylic acid and of α-substituted acrylic acid, such        as methacrylic acid, of nitriles, amides, alkyl esters such as        acrylonitrile, (meth)acrylamide, methyl (meth)acrylate, butyl        acrylate, ethyl acrylate, 2-ethylhexyl acrylate;    -   polymers of vinyl aromatic derivatives, such as styrene,        dichlorostyrene; chlorinated rubbers;    -   chlorinated polymers of olefins, such as ethylene, propene,        1-butene, (2.2.1)bicyclo heptene-2, (2.2.1)bicyclo        hepta-diene-2,5;    -   polymers and post-chlorinated polymers of chlorobutadiene and        copolymers thereof with vinyl chloride, chlorinated natural and        synthetic rubbers, and also mixtures of these polymers with one        another or with other polymerizable compounds.    -   grafted halogen containing copolymers, where the halogen        containing polymer part is grafted on an (meth)acrylic homo or        copolymer, in form of a particles, which could be crosslinked or        not.

Preferably the halogen containing polymer is a thermoplastic polymer andnot an elastomeric polymer. The glass transition temperature of thethermoplastic polymer is at least 40° C., preferably 50° C.

Preferably the halogen in the halogen containing polymer is chosen fromfluorine or chlorine and advantageously the halogen is chlorine.

The chlorine containing polymer is chosen from among polymers ormixtures of polymers chosen from among homopolymer vinyl chlorides suchas polyvinyl chloride, polyvinylidene chloride, chlorinated polyvinylchloride, post-chlorinated polyvinyl chloride and copolymers formed bythe polymerisation of a vinyl chloride monomer with up to 40% of acomonomer such as vinyl acetate, vinyl butyrate, vinylidene chloride,propylene, methyl methacrylate and the like, as well aschlorine-containing polymers containing other polymers such aschlorinated polyethylene, terpolymers of acrylonitrile, butadiene,styrene, terpolymers of methyl methacrylate, butadiene, styrene;polyacrylate resins, poly methyl methacrylate resins and terpolymer ofalkyl acrylate, methyl methacrylate, butadiene, preferably thechlorine-containing polymer is polyvinyl chloride or post-chlorinatedpolyvinyl chloride.

Preferably the chlorine containing polymer is chosen from homo- andcopolymers of vinyl chloride (VC); comprising at least 50 wt % of VCunits, preferably at least 70 wt % of VC units, more preferably at least80 wt % of VC units, advantageously at least 85 wt % of VC units; ormixtures thereof.

With regard to the process for preparing a polymeric composition P1according to the present invention comprising

-   -   a) from 30 wt % to 60 wt % of an inorganic compound (F)    -   b) from 2 wt % 15 wt % a (meth)acrylic copolymer (A1)    -   c) a polymeric impact modifier (IM1)        characterized that the three components of a), b) and c) add up        to 100 wt %, said process comprises the step of    -   blending the three components of a), b) and c), while the two        components of b) and c) and at least 83.33 wt % of compound        of a) are in form of a dispersion in aqueous phase during the        blending step.

With regard to a first preferred process for preparing a polymericcomposition P1 according to the present invention comprising

-   -   a) from 30 wt % to 60 wt % of an inorganic compound (F)    -   b) from 2 wt % 15 wt % a (meth)acrylic copolymer (A1)    -   c) a polymeric impact modifier (IM1)        characterized that the three components of a), b) and c) add up        to 100 wt %, said process comprises the step of    -   i) blending the three components of a), b) and c), while the two        components of b) and c) and at least 83.33 wt % of compound        of a) are in form of a dispersion in aqueous phase during the        blending step    -   ii) drying the blend obtained in step i).

With regard to a second preferred process for preparing a polymericcomposition P1 according to the present invention comprising

-   -   a) from 30 wt % to 60 wt % of an inorganic compound (F), said        inorganic compound (F) consists of a mineral filler (F1) and a        flow aid (F2), wherein the weight ratio (F1)/(F2) is at least        5/1,    -   b) from 2 wt % 15 wt % a (meth)acrylic copolymer (A1)    -   c) a polymeric impact modifier (IM1)        characterized that the three components of a), b) and c) add up        to 100 wt %, said process comprises the step of    -   blending the three components of a), b) and c), while the three        components b), c) and (F1) are in form of a dispersion in        aqueous phase during the blending step.

More preferably the process for preparing a polymeric composition P1comprising

-   -   a) from 30 wt % to 60 wt % of an inorganic compound (F) said        inorganic compound (F) consists of a mineral filler (F1) and a        flow aid (F2), wherein the weight ratio (F1)/(F2) is at least        5/1,    -   b) from 2 wt % 15 wt % a (meth)acrylic copolymer (A1)    -   c) a polymeric impact modifier (IM1)        characterized that the three components of a), b) and c) add up        to 100 wt %, said process comprises the step of    -   i) blending the three components a), b) and c), while the three        components b), c) and (F1) are in form of a dispersion in        aqueous phase during the blending step,    -   ii) drying the blend obtained in step i).

Additionally the process can include additionally the step of recoveringthe obtained blend of previous step in order to form a polymer powder oras a polymer powder.

The quantities of the aqueous dispersion of the three components of a),b) and c) or (F1) are chosen on the solid content of each respectivedispersion, in order to obtain the composition of polymeric compositionP1 on the solid part.

The recovering step of the process for manufacturing the polymercomposition according to the invention, is preferably made bycoagulation or by spray drying. It is obvious that the spray dryingcombines the recovering and drying in one process step.

In the case of spray drying it is possible to blend or mix therespective dispersions of the components of a), b) and c) before addingthe liquid mixture to the spray drying apparatus. It is also possible toblend or mix the dispersion inside the spray drying apparatus during therecovering step.

Spray drying is the preferred method for the recovering and/or dryingfor the process of preparing polymeric composition P1.

The polymeric composition P1 after drying comprises less than 3 wt %humidity and preferably less than 1.5 wt % humidity and more preferablyless than 1.2 wt % humidity.

The present invention relates also to a process for preparing apolymeric composition P2 comprising polymer composition P1, said polymercomposition P1 comprises

-   -   a) from 30 wt % to 60 wt % of an inorganic compound (F)    -   b) from 2 wt % 15 wt % a (meth)acrylic copolymer (A1)    -   c) a polymeric impact modifier (IM1),        characterized that the three components of a), b) and c) add up        to 100 wt %, and the said polymeric composition P2 comprises        also    -   d) a thermoplastic polymer TP1 said process comprises the step        of    -   blending the compositions P1 and the thermoplastic polymer TP1.

Preferably in the process for preparing a polymeric composition P2, thepolymer composition P1 is prepared according the process describedearlier.

The inorganic compound (F), the (meth)acrylic copolymer (A1), polymericimpact modifier (IM1), polymer composition P1 and thermoplastic polymerTP1 are the same as defined before.

Preferably blending the compositions P1 and the thermoplastic polymerTP1 is made by means known by one skilled in the art of blendingpolymeric compositions as dry blending or compounding of components thenmelt processed.

The ratio of the polymer composition P1 in the polymeric composition P2is between 1 and 20 phr, preferably between 2 and 15 phr, morepreferably between 3 and 12 phr and advantageously between 3 and 10 phr.

The present invention relates to the use of a polymeric composition P1comprising

-   -   a) from 30 wt % to 60 wt % of an inorganic compound (F)    -   b) from 2 wt % 15 wt % a (meth)acrylic copolymer (A1)    -   c) a polymeric impact modifier (IM1),        characterized that the three components of a), b) and c) add up        to 100 wt %, for increasing the melt fracture resistance of a        thermoplastic polymer TP1.

After the use, the thermoplastic polymer TP1 comprises the polymericcomposition P1 and gives polymeric composition P2.

Preferably in the process for preparing a polymeric composition P2, andthe polymer composition P1 is prepared according the processes describedearlier.

The inorganic compound (F), the (meth)acrylic copolymer (A1), polymericimpact modifier (IM1), polymer composition P1 and thermoplastic polymerTP1 are the same as defined before.

The present invention relates to the use of a polymeric composition P1comprising

-   -   a) from 30 wt % to 60 wt % of an inorganic compound (F)    -   b) from 2 wt % 15 wt % a (meth)acrylic copolymer (A1)    -   c) a polymeric impact modifier (IM1),        characterized that the three components of a), b) and c) add up        to 100 wt %, for transforming a polymeric composition P2 that        comprises said polymeric composition P1 and a thermoplastic        polymer TP1.

Preferably in the process for preparing a polymeric composition P2, thepolymer composition P1 is prepared according the process describedearlier.

The inorganic mineral filler (F), the (meth)acrylic copolymer (A1),polymeric impact modifier (IM1), polymer composition P1 andthermoplastic polymer TP1 are the same as defined before.

Preferably the transformation of polymeric composition P2 that comprisessaid polymeric composition P1 and a thermoplastic polymer TP1 is made byextrusion.

The polymer composition P1 is used in the polymeric composition P2 in aratio of between 1 and 20 phr, preferably between 2 and 15 phr, morepreferably between 3 and 12 phr and advantageously between 3 and 10 phr.

The present invention relates also to an article comprising thepolymeric composition P2 as described above. This article can be aprofile, a pipe, a siding, a flooring film, a sheet or a foamed article.

The present invention relates also to an article comprising thepolymeric composition P2 as described above, as a coextruded layer or aslayer of a laminated structure or as at least one layer of an multilayerstructure.

[Methods of Evaluation]

Glass Transition Temperature

The glass transitions (Tg) of the polymers or mixture of polymers aremeasured with equipment able to realize a thermo mechanical analysis. ARDAII “RHEOMETRICS DYNAMIC ANALYSER” proposed by the Rheometrics Companyhas been used. The thermo mechanical analysis measures precisely thevisco-elastics changes of a sample in function of the temperature, thestrain or the deformation applied. The used frequency is 1 Hz. Theapparatus records continuously, the sample deformation, keeping thestain fixed, during a controlled program of temperature variation.The results are obtained by drawing, in function of the temperature, theelastic modulus (G′), the loss modulus and the tan delta. The Tg ishigher temperature value read in the tan delta curve, when the derivedof tan delta is equal to zero.

For the estimation of volume average powder particle size, particle sizedistribution and ratio of fine particles a Malvern Mastersizer 300apparatus with a 300 mm lenses, measuring a range from 0.5-880 μm isused. The D (v, 0.5) is the particle size at which 50% of the sample hassize less then and 50% of the sample have a size larger then that size,or in other words the equivalent volume diameter at 50% cumulativevolume. This size is also known as volume medium diameter (abbreviatedD50) that is related to the mass or weight median diameter by thedensity of the particles assuming a size independent density for theparticles.

Molecular Weight

The mass average molecular weight (Mw) of the polymers is measured withby size exclusion chromatography (SEC).

Fusion Efficiency

The fusion efficiency of the polymer composition is estimated bymeasuring the fusion time with a torque rheometer based on ASTM D2538-02(reapproved 2010). A shorter fusion time signifies a better fusionefficiency and interpreted as a more efficient process.

Melt Strength

The melt strength was evaluated with a RHEOTENS GOTTFERT equipment whichwas used to compare the different melt strength of the respective PVCcomposition. Roll speed at break (mm/s) and strength at break (N) werereported to evaluate the melt fracture resistance of the differentcomposition.

Impact Strength

ASTM D5420 standard was used to evaluate the dart drop impact resistanceof the compositions. Normalized Mean Failure Energy (in*lbs/mil) wasreported for comparison.

The DIN 53753 method was used to evaluate the double V-notch impactstrength. 0.1 mm notch radius was used. Impact test were evaluated atcontrolled room temperature. Pendulum energy was 1J. 10 samples wereused to evaluate an average impact energy with its standard deviation.Information on the type of failure (Ductile or Fragile) is also given.

Microscopy

Microscopy on the powder is performed with Scanning Electron Microscopy(SEM). With the detection of back scattered electrons the inorganicfiller for example calcium carbonate can be easily detected in eachpowder grain.

Atomic Force Microscopy is performed in tapping mode in order to obtainabout the dissipated energy of the cantilever information about thevarying stiffness of the sample, due to different glass transitiontemperature of polymers and the inorganic filler.

EXAMPLES

Following materials are used or prepared:

The (meth)acrylic copolymer (A1) is prepared in this way:

A first (meth)acrylic copolymer (Ala): Charged into a reactor, withstirring, were 8600 g of water, 5.23 g of Na₂CO₃ and 38.20 g of sodiumlauryl sulfate, and the mixture was stirred until complete dissolution.Three vacuum-nitrogen purges were carried out in succession and thereactor left under a slight vacuum. The reactor was then heated. At thesame time, a mixture comprising 4166.4 g of methyl methacrylate and1041.6 g of n-butyl acrylate was nitrogen-degassed for 30 minutes. Next,the mixture was rapidly introduced into the reactor using a pump. Whenthe temperature of the reaction mixture reached 55 degrees centigrade,7.81 g of potassium persulfate dissolved in 98.08 g of water wereintroduced. The line was rinsed with 50 g of water. The reaction mixturewas left to rise in temperature to the exothermal peak. Thepolymerization was then left to completion for 60 minutes after theexothermal peak. The reactor was cooled down to 30 degrees centigradeand the latex dispersion removed. The solid content is 38.2%.

A second (meth)acrylic copolymer (A1b): Charged into a reactor, withstirring, were 8140 g of water, 5.23 g of Na₂CO₃ and 38.20 g of sodiumlauryl sulfate, and the mixture was stirred until complete dissolution.Three vacuum-nitrogen purges were carried out in succession and thereactor left under a slight vacuum. The reactor was then heated. At thesame time, a mixture comprising 3645.6 g of methyl methacrylate and1562.4 g of n-butyl acrylate was nitrogen-degassed for 30 minutes. Next,the mixture was rapidly introduced into the reactor using a pump. Whenthe temperature of the reaction mixture reached 55 degrees centigrade,7.81 g of potassium persulfate dissolved in 98.08 g of water wereintroduced. The line was rinsed with 50 g of water. The reaction mixturewas left to rise in temperature to the exothermal peak. Thepolymerization was then left to completion for 60 minutes after theexothermal peak. The reactor was cooled down to 30 degrees centigradeand the latex dispersion removed. The solid content is 39.5%.

A polymeric impact modifier (IM1) is prepared according to the techniquedescribed in U.S. Pat. No. 4,278,576, which employs a standard emulsionpolymerization technique.

A first polymeric impact modifier (IM1a) namely a core/shell acrylicpolymer impact modifier is prepared employing 89.2 parts of butylacrylate, 0.4 parts of butylene glycol diacrylate and 0.4 parts ofdiallymaleate as elastomeric core, followed by a polymerization of 10parts of methyl methacrylate. The solid content is 40% of the aqueousdispersion.

A second polymeric impact modifier (IM1b) namely also a core/shellacrylic polymer is prepared employing 84.2 parts of butyl acrylate, 0.4parts of butylene glycol diacrylate and 0.4 parts of diallymaleate aselastomeric core, followed by a polymerization of 15 parts of methylmethacrylate. The solid content is 40%.

The inorganic mineral filler (F1) is calcium carbonate (CaCO₃). Slurryor dispersion of CaCO₃ is prepared according to the technique describedin J.P. Pat. No. 59057913. Namely the slurry is obtained by mixing 270parts of water, 0.72 parts of sodium polyacrylate and 729.3 parts ofCaCO₃ of diam. 0.2-0.6 μm and 0.6% moisture and stirring for 20 min atshear rate 5 times 102/s. The obtained solid content is 73 wt %.

As thermoplastic polymer TP1, polyvinylchloride PVC S110P from Kemone isused.

As flow aid (F2) calcium carbonate (PCC, 0.07 micron) is used.

The sample compositions according to table 1 are prepared as polymercomposition P1 or as compositions for comparative examples in form ofpowders.

Comparative Example 1

The impact modifier dispersion (IM1a) and the slurry of mineral filler(F1) are mixed for with the following ratio, 7.902 kg (7902 parts) oflatex and 1.587 kg (1587 parts) of slurry, and spray dried in theconditions classically used for the dispersion alone. The obtainedpowder as a particle size˜150 μm. 3 weight percent calcium carbonate(PCC, 0.07 micron) is added to the recovered powder as a flow aid (F2).The resulting powder has a ratio of 70/30 acrylic impactmodifier/inorganic compound CaCO3.

Comparative Example 2

The impact modifier dispersion (IM1a) and the slurry of mineral filler(F1) are mixed for with the following ratio, 5.895 kg (5895 parts) oflatex and 2.469 kg (2469 parts) of slurry, and spray dried in theconditions classically used for the dispersion alone. The obtainedpowder as a particle size ˜150 μm. 3 weight percent calcium carbonate(PCC, 0.07 micron) is added to the recovered powder as a flow aid (F2).The resulting powder has a ratio of 55/45 impact modifier/inorganiccompound CaCO3.

Comparative Example 3

For this comparative example each components is spray dried alone andthen the obtained powders are mixed together with 3 weight percentcalcium carbonate (PCC, 0.07 micron) as flow aid. Thus enough impactmodifier dispersion (IM1a) is spray dried in order to obtain 2122 g ofpowder. Enough process aid (meth)acrylic copolymer (Ala) dispersion isspray dried in order to obtain 235.8 g of powder. Enough calciumcarbonate slurry is spray dried in order to obtain 1800 g of calciumcarbonate. These 3 amounts of powder are dry blended with 128.6 g ofCalcium carbonate (PCC, 0.07 micron) in order to obtain a dry blendcomposite.

Example 1

The two acrylic dispersions and the inorganic slurry are mixed for withthe following ratio, 5.305 kg (5305 parts) of impact modifier dispersion(IM1a), 0.617 kg (617 parts) of process aid (meth)acrylic copolymer(Ala) and 2.469 kg (2469 parts) of slurry of inorganic mineral filler(F1), and spray dried in the conditions classically used for thedispersion alone. The obtained powder as a particle size˜150 μm. 3weight percent calcium carbonate (PCC, 0.07 micron) is added to therecovered powder as a flow aid (F2). The resulting powder has a ratio of55/45 polymer/inorganic compound CaCO3.

Example 2

Example 1 is repeated but impact modifier dispersion (IM1b) is usedinstead of impact modifier dispersion (IM1a).

Example 3

Example 1 is repeated but(meth)acrylic copolymer (A1b) is used insteadof (meth)acrylic copolymer (A1a).

TABLE 1 Composition of powder samples Flow aid F = A1 IM1 (F1) (F2) F1 +F2 [wt %] [wt %] [wt %] [wt %] [wt %] Comparative 0 70 27 3 30 example 1Comparitive 0 55 42 3 45 example 2 Comparitive 5.5 49.5 42 3 45 example3 Example 1 5.5 49.5 42 3 45 Example 2 5.5 49.5 42 3 45 Example 3 5.549.5 42 3 45

The prepared powder samples of comparative examples and examples oftable 1 are formulated at 5.5 phr in a PVC composition with PVC asthermoplastic polymer TP1. The compositions are dry blended in aPapenmeyer equipment while increasing the temperature. PVC compositionsare prepared according to quantities given in table 2.

TABLE 2 PVC compositions Composition with components quantities in phrPVC (TP1) 100 100* 1pack CaZn 4 4 CaCo3 filler 8 22 TiO2 8 0 Addedpolymeric 5.5 4 composition from respective comparative examples andexamples (P1) *Composition for GARDNER falling weight impact strength

The different compositions of table 2 where process extruded in a HaakePolylab extruder. During the extrusion the average torque and fusionpressure were followed.

The results are summarized in table 2.

TABLE 3 Evaluation of the respective examples and comparative examplesof table 1 during transformation and extrusion of composition of table 2Fusion Fusion Roll speed Stength Torque Pressure time at break at break[%] [bar] [s] [mm/s] [N] Comparative 66 134 185 67 0.92 example 1Comparitive 66 131 192 52 0.90 example 2 Comparitive 67 132 185 — —example 3 Example 1 63 125 175 82 1.01 Example 2 62 124 186 — — Example3 64 128 148 87 1.00

The examples 1 to 3 show a lower torque and fusion pressure, whilehaving better or acceptable fusion time, and especially a much higherroll speed at break and strength at break, allowing a faster extrusiondue to better melt fracture resistance.

Comparative examples 1 and 2, have a higher fusion pressure and torqueand lower higher roll speed at break and strength at break, whilecomparative example 3 has a higher fusion pressure and torque.

Specimen were prepared from extruded samples according to composition oftable 2, while using examples and comparative examples of powder samplecompositions of table 1. Impact properties were measure of specimens andresults are given in table 4.

TABLE 4 Evaluation of impact properties of the respective examples andcomparative examples of table 1 after transformation and extrusion ofcomposition of table 2. GARDNER falling Double weight impact V-notchstrength impact strength % of ASTM D5420 DIN 53753 ductile [in *lbs/mil] [kJ/m2] break Comparative 2.2 n.m. n.m. example 1 Comparitive1.6 n.m. n.m. example 2 Example 1 2.4 47.4 100% Example 2 2.2 36.0  30%Example 3 n.m. n.m. n.m. n.m.—not measured

The examples 1 and 2 show the same level or even higher of fallingweight impact strength, while the composition comprises less impactmodifier than comparative examples.

The invention claimed is:
 1. A dry polymer composition P1 comprising: a)from 30 wt % to 60 wt % of an inorganic mineral compound (F), b) from 2wt % to 15 wt % of a (meth)acrylic copolymer (A1) or a mixture of(meth)acrylic copolymers comprising at least 50 wt % of polymeric unitscoming from methyl methacrylate and having a glass transitiontemperature Tg between 60° C. and 106° C., c) a polymeric impactmodifier (IM1) or a mixture of polymeric impact modifiers, wherein saidpolymeric impact modifier (IM1) is a multistage polymer particle havinga multilayer structure comprising at least one layer (IM1L1) comprisinga polymer (L1) having a glass transition temperature between −100° C.and 0° C. and at least another layer (IM1L2) comprising a polymer (L2)having a glass transition temperature between 60° C. and 150° C.,wherein the three components of a), b) and c) add up to 100 wt %,wherein the weight ratio of layer (IM1L1)/layer (IM1L2) in themultistage polymer is at least 85/15; and wherein said dry polymercomposition P1 comprises less than 3% humidity.
 2. The compositionaccording to claim 1, wherein the inorganic compound (F) consists of amineral filler (F1) and a flow aid (F2), wherein the weight ratio(F1)/(F2) is at least 5/1.
 3. The composition according to claim1—comprising a) between 30 wt % and 60 wt % of an inorganic mineralcompound (F), b) between 2 wt % and 15 wt % a (meth)acrylic copolymer(A1) and c) a polymeric impact modifier (IM1).
 4. The compositionaccording to claim 1, wherein the composition is in form of a powderhaving volume median particle size D50 between 1 μm and 500 μm.
 5. Thecomposition according to claim 4, wherein each powder particle comprisesthe compounds of a), b) and c).
 6. The composition according to claim 1,wherein the weight ratio of layer (IM1L1)/layer (IM1L2) in themultistage polymer is at least 87/13.
 7. The composition according toclaim 1, wherein the weight ratio of layer (IM1L1)/layer (IM1L2) in themultistage polymer is in a range by weight between 86/14 and 97/3. 8.The composition according to claim 1, wherein the polymer L1 presentsmore than 85 wt % of the polymeric impact modifier (IM1).
 9. Thecomposition according to claim 1, wherein the polymer L1 presents morethan 86 wt %.
 10. The composition according to claim 1, wherein thepolymer (L1) having a glass transition temperature between −100° C. and0° C. is a (meth) acrylic polymer comprising at least 50 wt % ofmonomers from alkyl acrylates.
 11. The composition according to claim 1wherein at least a part of the inorganic mineral filler (F) is a mineralfiller chosen from the group consisting of calcium carbonate, calcinatedclay, silica (fumed or precipitated), clay, Montmorillonite nano-clay,zeolite, perlite, and titanium dioxide.
 12. The composition according toclaim 1 wherein the inorganic mineral filler (F) or the mixture thereofis chosen from calcium carbonate.
 13. The composition according to claim1 wherein the (meth)acrylic copolymer (A1) is chosen from the groupconsisting of copolymer comprising at least 50 wt % of methylmethacrylate.
 14. The composition according to claim 1 wherein the(meth)acrylic copolymer (A1) has a weight average molecular weight of atleast 1,000,000 g/mol.
 15. A process for preparing a dry polymericcomposition P1 comprising a) from 30 wt % to 60 wt % of an inorganiccompound (F) b) from 2 wt % to 15 wt % of a (meth)acrylic copolymer (A1)comprising at least 50 wt % of polymeric units coming from methylmethacrylate and having a glass transition temperature Tg between 60° C.and 106° C., c) a polymeric impact modifier (IM1), wherein saidpolymeric impact modifier (IM1) is a multistage polymer particle havinga multilayer structure comprising at least one layer (IM1L1) comprisinga polymer (L1) having a glass transition temperature between −100° C.and 0° C. and at least another layer (IM1L2) comprising a polymer (L2)having a glass transition temperature between 60° C. and 150° C., andwherein the weight ratio of layer (IM1L1)/layer (IM1L2) in themultistage polymer is at least 85/15, wherein the three components a),b) and c) add up to 100 wt %, said process comprising the steps of:blending the three components of a), b) and c), while the two componentsb) and c) and at least 83.33 wt % of compound a) are in form of adispersion in aqueous phase during the blending step to obtain a blend,and drying said blend until said dry polymeric composition P1 comprisesless than 3% humidity.
 16. The process for preparing a composition P1according to claim 15 wherein said inorganic compound (F) consists of amineral filler (F1) and a flow aid (F2), wherein the weight ratio(F1)/(F2) is at least 5/1.
 17. The process according to claim 15,wherein said process comprises the steps of: i) blending the threecomponents of a), b) and c), while the three components are in form of adispersion in aqueous phase during the blending step, ii) drying theblend obtained in step i).
 18. The process for preparing a polymericcomposition P2 comprising polymer composition P1 according to claim 1,wherein the said polymeric composition P2 further comprises d) athermoplastic polymer TP1, said process comprising the step of: blendingthe compositions P1 and the thermoplastic polymer TP1.
 19. An articlecomprising transformed polymer composition according to claim 16,wherein the article is a profile, a pipe, a siding, a flooring film,sheet or foamed article.